Hornblend and Optical Glasses

This is a hornblend crystal and two different optical glasses in a mounting medium of 1.664 refractive refractive index index medium. The 1.64 refractive index glass is in moderate relief along the left edge of the image. The hornblend and the 1.67 refractive index optical glass are in clearly visible as a result of the dispersion colors. Dispersion colors are evident in the hornblend particle even though it is naturally colored.